This invention relates to watertight bushing and bolt mounting assemblies.
Insulator bushings are used to safely convey an electrical wire, cable or other electrical conductor or device through a metal enclosure wall containing electrical equipment. When such electrical equipment enclosures are located outdoors or otherwise in possibly wet or damp environments, it is of the utmost importance that the enclosure be sealed against moisture to prevent damage to the enclosed electrical equipment.
Accordingly, numerous devices have been designed for sealingly mounting electrical insulator bushings. In U.S. Pat. No. 2,597,596 issued to Reid, an insulator bushing is provided with an annular shoulder which bears against a gasket ring. The gasket ring rests in the annular groove surrounding the opening in the side wall of the container to provide the needed seal. The collar is pressed against the gasket by a clamp which is mounted to the wall by means of screws. The screws extend through the clamp and into, but not through, the wall.
In U.S. Pat. No. 2,179,356 of Skvortzoff, a gasket is pressed between a bushing shoulder and an upturned annular wall surrounding an opening in the enclosure wall by means of clamps. The clamps are secured by bolts especially welded to the enclosure wall.
A structure used for mounting a condenser bushing is shown in U.S. Pat. No. 3,055,968 of Spiece that is similar to the assembly of Reid 2,597,596, but in which the clamp is secured by bolts that extend into threaded metal grommets especially attached to the wall for that purpose.
Other similar structures are also shown in U.S. Pat. No. 2,300,195 of Bennett; U.S. Pat. No. 2,343,210 of Vienneau and U.S. Pat. No. 3,054,975 of Barr.
All of the assemblies shown in these patents suffer from one of these disadvantages. Some of these mounting assemblies require an enclosure wall of sufficient thickness to provide adequate support for a screw or the like. Others require provision of special grooves in the wall or special connectors, such as bolts or grommets, fixedly secured to the wall by means of welding.